The present invention relates to a device for detection of infrared rays, and particularly a device of the kind that initiates the ignition of an explosive charge when the device is in the vicinity of a target that emits infrared radiation. Such devices are previously known, and are called passive IR proximity fuzes, and are intended to be included in projectiles, for example, that move with a high velocity towards the target.
One of the problems involved with such a device is to distinguish between solar radiation and the IR radiation emitted from the target, as the sun constitutes a very strong source of radiation in the IR range. It is, indeed, known in the art to make proximity fuzes that can carry out this operation. Two diverging coaxial rotation-symmetrical conical fields of view are then utilized, and a target passage is then characterized in that the IR radiation caused by translational movement of the projectile in relation to the target is received in both fields of view in rapid succession, while the divergence between the fields of view has the result that sources of radiation at great distances (the sun) can only be perceived in one of the fields of view. The fields of view are then comprised in separate receiver channels.